Basic research on membrane transport could help people affected by cystic fibrosis or suffering from high blood pressure, according to Rémy Sauvé, Professor in the Department of Physiology at Université de Montréal and member of the Membrane Transport Research Group. He is interested in potassium channels and the role they may play in the process of mucus secretion and control of arterial pressure.

Secretion of pulmonary mucus is a major problem for individuals afflicted with cystic fibrosis: an accumulation of thick mucus makes the elimination of bacteria difficult, and this leads to pulmonary infections. "For these individuals, there is a problem of dryness and viscosity of pulmonary secretions because the water molecules do not pass through the mucous membrane," the Professor explains. "There is a close link between the quantity of water contained in pulmonary secretions and the movement of chloride through cellular membranes."

In cases of cystic fibrosis, the protein responsible for moving chloride does not work as it should, and the mucus becomes dry. Several strategies are currently under study to correct this defect in chloride secretion. The one occupying Professor Sauvé's attention involves forcing chloride secretion by stimulating potassium secretion. "We know that activating the potassium channel stimulates the secretion of chloride," he explains. "And the secretion of potassium chloride would in turn allow water to pass by osmosis."

Pharmacological interventions designed to activate potassium channels could also be used to treat arterial hypertension. This anomaly is created in part by excessive contraction of the muscles surrounding blood vessels, which obstructs blood circulation. In addition, activation of potassium channels encourages the proliferation of T-lymphocytes, which play an essential role in our immune system. Inhibition of these channels thus represents a way to suppress the immune response, which causes problems for organ transplants.

This sort of application requires more knowledge of the atomic structure and functioning of the potassium channels, the goal of the basic research being done by Professor Rémy Sauvé and his team. The Membrane Transport Research Group is studying ion and nutrient exchange between the cell's internal and external milieus. These exchanges are carried out by proteins that form the channels through which the ions can circulate. The channels are specialized, each one allowing only one type of ion through-potassium, chloride or sodium.

Researcher: Remy Sauvé
Telephone: (514) 343-7924
Funding: Canadian Institutes of Health Research, Canadian Cystic Fibrosis Foundation, Fondation des maladies du cœur du Québec